Study of the influence of UV-irradiation on the photodegradation of plasticized poly(para-tert-butylstyrene) films

Abstract

Abstract The photodegradation of thin films of poly(para-tert-butylstyrene) with 265 nm radiation in the presence of oxygen, and as a function of irradiation time, has been studied using fluorescence, Fourier transform-infrared spectroscopy, and ultraviolet-visible spectroscopy. The influence of phthalate and terephthalate plasticizers on photo-oxidative degradation was also investigated. Blending with phthalate plasticizers was found to cause a higher efficiency of degradation than that obtained for doping with terephthalate plasticizers. The intensity of absorption was also found to increase with time of irradiation and in the intensity of a new absorption band at longer wavelength, thus indicating a possibility of photodegradation of polymer films. The analysis of the Fourier transform-infrared spectra of the irradiated and non-irradiated samples showed an increase in the intensities of the carbonyl and hydroxyl regions of the Fourier transform-infrared spectra providing evidence for the photodegradation as well as the photo-oxidation of polymeric chains. The increase in the analyzed ranges is attributed to the formation of alcohols, aliphatic ketones and to the increase in the number of polyene structures that resulted from hydrogen abstraction during photodegradation reactions.